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Cardiac adaptation to obesity and hypertension after heart transplantation
H O Ventura1, M R Johnson, B Grusk
1Department of Internal Medicine, Loyola University Medical Center, Illinois 60153.
Insights
Obese heart transplant patients develop cardiac changes including increased cardiac output and left ventricular mass. These adaptations may raise the long-term risk of graft failure due to a lower left ventricular ejection fraction.
Area of Science:
- Cardiology
- Transplantation Medicine
- Obesity Research
Background:
- Obesity and hypertension are common post-heart transplantation complications.
- Understanding cardiac adaptation in these patients is crucial for long-term outcomes.
Purpose of the Study:
- To investigate cardiac adaptation in obese hypertensive heart transplant recipients.
- To compare hemodynamic and echocardiographic indexes between obese and non-obese hypertensive patients one year post-transplant.
Main Methods:
- Matched case-control study comparing 10 obese hypertensive patients with 10 non-obese hypertensive patients.
- Assessment of hemodynamic (cardiac output, systemic vascular resistance) and echocardiographic (left ventricular dimensions, mass, ejection fraction) parameters.
- Patients were evaluated one year after cardiac transplantation.
Main Results:
- Obese patients exhibited 30% greater cardiac output and 25% lower systemic vascular resistance.
- Significantly higher right ventricular and pulmonary artery pressures were observed in obese patients.
- Obese patients showed increased left ventricular end-diastolic diameter, mass, and volume, but a lower left ventricular ejection fraction (34% vs. 51%).
Conclusions:
- Cardiac adaptation in obese hypertensive heart transplant patients involves left ventricular dilation and increased mass, with higher cardiac output and lower peripheral resistance.
- These adaptive changes may increase the risk of graft failure, indicated by reduced left ventricular ejection fraction.
- Further research is needed to mitigate these risks and improve long-term graft survival.
Abstract:
Obesity and hypertension frequently develop after heart transplantation. The cardiac adaptation to obesity and hypertension was studied by determining hemodynamic and echocardiographic indexes in 10 obese hypertensive patients (body mass index greater than or equal to 27.8 kg/m2 in men or greater than or equal to 27.3 kg/m2 in women) matched by mean arterial pressure, age and gender with 10 nonobese hypertensive patients 1 year after cardiac transplantation. Cardiac output was 30% greater (p less than 0.02) and systemic vascular resistance 25% lower (p less than 0.01) in the obese than in the nonobese patients. Right ventricular systolic and pulmonary artery systolic, diastolic and mean pressures were also significantly higher (p less than 0.05) in the obese patients. Left ventricular end-diastolic diameter was 25% greater (p less than 0.05), left ventricular mass 28% greater (p less than 0.02) and left ventricular end-diastolic volume 20% higher (p less than 0.01) in the obese subjects. Left ventricular ejection fraction was significantly lower in the obese than in the nonobese subjects (34% vs. 51%, p less than 0.05). These results indicate that the cardiac adaptation to obesity and hypertension after heart transplantation consists of left ventricular dilation and an increase in left ventricular mass associated with an increased cardiac output and lower peripheral vascular resistance. These adaptive changes that occur in obese hypertensive patients after heart transplantation might increase the long-term risk of graft failure, as suggested by their lower left ventricular ejection fraction 1 year after transplantation.